The present invention discloses a system and method that is capable of coordinating between manual and automatic dispatching system by providing a tool control system and method having a pre-dispatch capability for relaxing the loading of a dispatch system so that the dispatching system can focus on production lots only.
In a full-automation fab for manufacturing of semiconductor wafers or other wafer technology, an intrabay transportation facility is used. The intrabay transportation facility uses automatic guided vehicles (AGV) to dispatch and transport wafers from various load ports and processing equipment during wafer fabrication. In a wafer foundry fab, there is considerable mixing of products requiring a complex process flow thus making a dispatching system difficult to implement. The system capabilities of the existing dispatching systems are not flexible enough to conform to the flow of a variety of semiconductor production processes.
Existing dispatching systems handle both representative lot control and automated wafer dispatching. Scheduling of representative wafer lots for use in a statistical process control process must be done in advance for existing automated wafer fabs and such representative lots are not easily monitored by operators of the dispatching system.
Existing dispatch systems do not allow for multi-lot processing but rather, require operators to dispatch each lot of wafers to each piece of fabrication equipment by separately issuing detailed transfer commands from a work in process list to each equipment port for transferring a lot of wafers to another equipment port. Such an existing system does not provide for optimal lot, high priority, or batch processing.
A wafer holding device such as a Front Opening Unified Pod (FOUP) typically, capable of holding up to 25 wafers, may transport only one lot at a time, wherein each lot is often less than 25 wafers. Additionally, existing dispatching systems provide a time delay for handling super hot or high priority lots that may not be compatible with real time activity. A means for handling high priority or multiple lots within a single FOUP for processing by many pieces of fabrication equipment requires extreme complexity in existing systems, probably beyond an operator""s capability to handle.
Additionally, existing dispatching systems used in a full automatic fab do not provide coordination between manual dispatching and automatic dispatching. Thus, existing automated fabs do not provide means for manually handling lots of wafers ready for dispatching to a fabrication machine. When manual insertion of a lot of wafers is needed, considerable downtime results, thus, severely impacting system performance. Therefore, a simplified methodology for using manual and automatic dispatching is essential.
It is desirable to provide a prioritized queue of FOUPs, each FOUP having multiple lots disposed within for transfer to at least one piece of fabrication equipment.
It is desirable to provide a dispatching list having meaningful lot sequence for each fabrication equipment used in the fabrication process.
It is desirable to provide an adjustable sequence of lots or jobs in a dispatching queue that is adjustable for dynamic dispatching priority changes.
It is desirable to relax loading of a dispatching system within a wafer fabrication facility.
It is desirable to provide a coordination model between manual and automatic dispatching within an automated fabrication process.
It is desirable to provide a smooth super hot lots handling model in a full automatic fab.
It is desirable to provide daily monitoring support for a full automatic fab.
It is desirable to provide batching equipment support to optimize processing of wafers in a batch type processing fabrication equipment.
It is desirable to provide a loose reservation between pre-dispatch jobs and each piece of fabrication equipment.
It is desirable to provide a method providing a new operating flow for an automated fabrication process.
In general present invention provides a system and method for coordination between a manual and an automatic dispatching system by using a tool control system (TCS) having a dispatching capability to allow for automatic handling and a pre-dispatching capability to allow manual handling in a full automatic fab. More particularly, the TCS system provides for managing wafer fabrication in a wafer fabrication process, the total control system having:
a) a plurality of FOUPs for holding at least one lot of wafers;
b) an overhead transport system for transporting FOUPs from a first location to a second location;
c) a sorter for sorting a plurality of wafer lots according to a sequence defined by the tool control system for insertion into an individual FOUP or multiple FOUPs;
d) a ceiling loader and hanger for inserting and removing FOUPs from the overhead transport system;
e) a buffer holding area for buffering FOUPs waiting to be inserted into the overhead transport system;
f) at least one piece of fabrication equipment; and an operation management interface providing an interface for an operator to communicate with the tool control system and with the at least one piece of processing equipment to allow coordination between manual and automatic dispatching of FOUPS to the at least one piece of fabrication equipment within a full automatic fab.
TCS may be operated in an automated or in a manual dispatching mode using the OMI to control dispatching of FOUPs within the TCS. The operation management interface of the TCS preferably has a work in progress portion, a selected lots configurable portion, and a pre-dispatch list portion.
Additionally, a method of using a tool control system to control and manage a wafer fabrication process during an automated mode and during a manual mode is disclosed. The method providing the steps of
a) using an operation management interface to dispatch wafers to an at least one piece of fabrication equipment upon occurrence of a triggering event, the triggering event occurring when a first load port tool for the piece of fabrication equipment becomes empty;
b) checking the at least one piece of fabrication equipment""s processing status;
c) issuing a move in request to an operation job supervisor if the at least one piece of fabrication equipment having a first load port is ready to receive a FOUP;
d) querying the at least one piece of fabrication equipment""s processing status until the at least one piece of fabrication equipment signals that it is ready to receive a FOUP;
e) determining if a pre-dispatch list is empty;
f) collecting FOUP status information if the pre-dispatch list is not empty;
g) selecting lots from a work in progress list to create a selected lots list in a selected lots configurable portion of the operation management interface if the pre-dispatch list is empty;
h) transferring the selected lots list from the selected lots configurable portion of the operation management interface to the pre-dispatch portion to create a pre-dispatch list;
i) determining if a FOUP containing the pre-dispatched lots identified at the top of the pre-dispatch list is available to be loaded onto an overhead transport system;
j) waiting a predefined length of time if the FOUP containing the pre-dispatched lots identified at the top of the list is not available before verifying again that the FOUP identified at the top of the pre-dispatch list is available to be loaded onto the overhead transport system;
k) identifying to a FOUP queue that the FOUP containing the pre-dispatched lots identified at the top of the pre-dispatch list will be assigned to the specific piece of fabrication equipment;
l) identifying placement of the FOUP within the FOUP queue;
m) removing the lots contained within the FOUP from the pre-dispatch list if the FOUP is available for loading onto the overhead transport system;
n) issuing a transfer command to the MCS to load the FOUP onto the overhead transport system for transferring the FOUP to the at least one piece of fabrication equipment;
o) identifying that the FOUP is loaded onto the first load port of the at least one piece of fabrication equipment;
p) verifying the pre-dispatch lots listed in the FOUP are delivered to the at least one piece of fabrication equipment; and
q) communicating the verification from the tool control system to the at least one piece of fabrication equipment so that the at least one piece of fabrication equipment selectively start an appropriate fabrication operation for the specific lots delivered.